1. Delete all copies of gbaframe.bmp from the _system_ folder and the _system_\themes\themeXX folders on the microSD card. This will remove the border image, but there will still be a black border around the edge of the screen when playing GBA games.

2. The 3-in-1 has 32MB (megabytes) of NOR flash memory, and 16MB of PSRAM. You can run GBA games from either, but games larger than 16MB won't fit in PSRAM.

The PSRAM is volatile memory; it can only retain data while the power is on. It takes about 1 second per megabyte to copy games into PSRAM, and this must be done each time you want to play a game.

NOR flash memory is non-volatile memory; once data is written to it, it stays there until it is erased and rewritten. It takes much longer to copy a game to NOR (up to nearly five minutes for the largest games), but once a game is in NOR it will start instantly. The 3-in-1 can be used like a regular GBA game cart when a game is in NOR.

3. I'm not sure what you mean by this. The process for running GBA games is as follows: SRAM patch the game with GBATA, put it on the memory card, and run it from PSRAM or copy it to NOR.

4. Not that I know of, but "2 in 1: Dr. Mario & Puzzle League" apparently can't be SRAM patched, so it can't save. It still runs though.

5. This will boot the slot 2 cart. If you have a game written to NOR, you can launch it with this button rather than starting it from the 3in1 Expansion Pack Tool.

This option will also allow you to run DS software in .ds.gba form (that's an .nds file with a special loader attached to it, mainly used for homebrew) from the 3-in-1, though there isn't much DS software that needs to be run from a slot 2 cart these days.